Paying for no service

I have been struggling with slow and no internet for the last two months phoning Amobia almost every second day. I have pleaded with them to send out a technician to resolve this problem because I don't feel like going through the effort of moving to a different service provider. Every time I phone they make a few changes on their side only to have the same problem the next day. I phoned them again on Monday and the support desk said they would investigate and phone me back in a few minutes. I am still waiting for their call. I phoned again today as I dant have ANY Internet and they aren't even answering the phone. I am paying R499 a month for a 2mbps uncapped line and I have about 2 days working Internet a week and even then it is so slow it is unbearable to use.